Date   

Re: ERA-02 as a multiplier

Colin Ranson
 

Andy, I just happened to have two separate 723’s on a piece of veroboard that came with a W1GHz  simple personal beacon for 10GHz. (bought at a uW MRT many years ago) Each one was used to control the bias on the Multiplier MODAMPS.

 

Just seemed handy to use !   I will of course use something more appropriate like an LDO1117 adj. Or similar when I lay out the PCB.

 

Colin de ‘LBS.

 

 

Sent from Mail for Windows 10

 

From: Andy G4JNT
Sent: 24 January 2021 22:30
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] ERA-02 as a multiplier

 

Ouch

Still using the 723 regulator?

That thing is so complicated to connect up compared with an LM317.  And, I believe, a lot noisier.   

Isn't it so old that the reference inside it is an actual Zener?  If so, no wonder it's noisy.

I formally learnt about them in 1976 - remember it well.

 

Andy

 

 

 

On Sun, 24 Jan 2021 at 22:26, Colin Ranson <g8lbs@...> wrote:

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 

 


Re: Gap Waveguides

Ethan Waldo
 

Thanks for responding.  As I said copper electrodeposition seems feasible for amateurs and gets from 4um to 400um accuracy in lieu of micromachining, but is a lot slower.  I'm curious if air is the effective dielectric, do you use a dielectric constant of 1 in calculations or some very small number?


Re: ERA-02 as a multiplier

Andy G4JNT
 

Ouch
Still using the 723 regulator?
That thing is so complicated to connect up compared with an LM317.  And, I believe, a lot noisier.   
Isn't it so old that the reference inside it is an actual Zener?  If so, no wonder it's noisy.
I formally learnt about them in 1976 - remember it well.



On Sun, 24 Jan 2021 at 22:26, Colin Ranson <g8lbs@...> wrote:

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 


Re: ERA-02 as a multiplier

Colin Ranson
 

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 


Re: ERA-02 as a multiplier

geoffrey pike
 

But when you get to 10.5 GHz you will probably want to amplify that so perhaps just get a handful of NLB-310 from the outset
(which i use in my multiplier), But perhaps you have a handful of ERA-02s that you want to use up. 
cheers
Geoff
GI0GDP
(-2C outside)

On Sunday, 24 January 2021, 19:36:57 GMT, Greg - ZL3IX <zl3ix@...> wrote:


Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: ERA-02 as a multiplier

Andy G4JNT
 

Yes, I've used then for both X3 and X4 to 10GHz.  They work very well.   Operate at a bit lower than the recommended bias level to increase non-linearity.
IIRC, I got something like 0dB tripler gain at 0dBm.   May have remembered that wrongly tho.
Try it and see - play with the optimum biassing.

And, BTW,   an MSA family modamp was used as a doubler in the Inmarsat-3 satellite, in the frequency generator module.
So if it's good enough for a spacecraft ...



On Sun, 24 Jan 2021 at 19:36, Greg - ZL3IX <zl3ix@...> wrote:
Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: ERA-02 as a multiplier

KENT BRITAIN
 

According to Zack at the ARRL, they have modest harmonics out to 24 GHz.
Kent  WA5VJB/2E0VAA


On Sunday, January 24, 2021, 01:36:57 PM CST, Greg - ZL3IX <zl3ix@...> wrote:


Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


ERA-02 as a multiplier

Greg - ZL3IX
 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: Are LEDs a noise source

Neil Smith G4DBN
 

Perhaps adding a piezo element and lightweight front-silvered mirror on a low-mass flexure into the path would give sufficient bandwidth for modulation into the kHz range so you could drive it directly with soundcard output from WSJT-X.

Neil G4DBN

On 24/01/2021 19:09, KENT BRITAIN wrote:
We mechanically modulated ours.  Much easier!  
Simplest was to just run the beam though the blades of a muffin fan. 
Turning the fan at about a 45 deg angle greatly improved the on to off ratio.  
With a more controlled motor and disk with a pattern of holes,   
 precise modulation tones can be produced.
  Kent

On Sunday, January 24, 2021, 12:16:44 PM CST, Robin Szemeti - G1YFG <robin@...> wrote:


It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG

--
Robin Szemeti - G1YFG
-- 
Neil
http://g4dbn.uk


Re: Are LEDs a noise source

KENT BRITAIN
 

We mechanically modulated ours.  Much easier!  
Simplest was to just run the beam though the blades of a muffin fan. 
Turning the fan at about a 45 deg angle greatly improved the on to off ratio.  
With a more controlled motor and disk with a pattern of holes,   
 precise modulation tones can be produced.
  Kent

On Sunday, January 24, 2021, 12:16:44 PM CST, Robin Szemeti - G1YFG <robin@...> wrote:


It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Robin Szemeti - G1YFG
 

It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Andy G4JNT
 

Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Andy G4JNT
 

You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Robin Szemeti - G1YFG
 

I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W


On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Neil Smith G4DBN
 

Back on to the original topic for a second, there are some articles showing what appears to a forward-biased LED used as a noise source. The author in this piece says the noise was about 6dB down on a zener in the same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being used in reverse breakdown.  The diagram towards the end of the page definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10 kHz, but that is at low levels. However, at high currents, the authors found a correlation between the LF noise and the brightness fluctuations of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED and photodiode are used to generate noise with 7dB ENR up to about 100 MHz, but it hits the usual 1/f noise issues. https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random pulse generator, but that's well away from the OP's question.

Neil G4DBN


Re: Are LEDs a noise source

KENT BRITAIN
 

I was also done along the Gulf of Mexico in the 1970's using Xenon flash tubes and
light intensifiers.   No digital processing and got 300 km on clear nights.  
Sea level to sea level, just scatter.
Certainly another 30 or 40 dB more power in the sources.
Be sure to have deep 100 Hz and/or 120 Hz filters.
Hard to think of a common incandescent light bulb as a frequency doubler, but they
do respond to both peaks in a sine wave. 
I have 6 systems we used several times during VHF/UHF contests.
We used the Lasers out of CD players.   IR and power adjustable.
The best detectors were made by Texas Instruments for Laser guided bombs,
but a panel of solar cells also worked well.   LOTS of capture area.

Kent

On Sunday, January 24, 2021, 10:25:33 AM CST, Andy G4JNT <andy.g4jnt@...> wrote:


No, It WAS done yonks ago in Oz, using WSPR just after it first came out

They used 60W of red LEDs, WSPR on a subcarrier and got 200km plus on cloud scatter.

I keep thinking I really ought to have a go at this, get some really big high power RED LEDs and find some suitable optics.    It's difficult getting a non point source into a narrow beam though, needs physically big and thick lenses.



On Sun, 24 Jan 2021 at 16:22, John Fell <john.g0api@...> wrote:
-45dB would probably relate to the developmental WSJT-X software yet to be released .(Done in VK ?)

I have had Transatlantic decodes at -44dB/noise , using JST4W-1800 on 137kHz  - that seems to be the limit but up in the realtime nano metre wavelengths , with massive path scattering a 65 tone or more system would need to be used .
Andy JNT knows more about the Shannon theory ....but all the LEDs in his right side are aching again .I blame the Snow .

It's Bloody clever stuf .

73
John
G0API

On Sun, 24 Jan 2021 at 16:09, Robin Szemeti - G1YFG <robin@...> wrote:
Speaking of which ... there was a rather excellent article in DUBUS a while ago about some chaps resurrecting a 90's LED optical transceiver and adding JT65 or similar to it and getting phenomenal performance ... hundreds of kilometres over non-line-of-sight paths, just relying on atmospheric scattering and recovering signals at -45 dB S/N

On Sun, 24 Jan 2021 at 14:53, Andy G4JNT <andy.g4jnt@...> wrote:
Especially white ones.



On Sun, 24 Jan 2021 at 14:34, John E. Beech <john@...> wrote:
It could be argued that LEDs produce noise at nanometer wavelengths.

de John G8SEQ

>  -------Original Message-------
>  From: Andy G4JNT <andy.g4jnt@...>
>  To: UK Microwaves groups.io <UKMicrowaves@groups.io>
>  Subject: Re: [UKMicrowaves] Are LEDs a noise source
>  Sent: Jan 23 '21 20:36

>  LEDs do not generate noise. Being forward-biassed, there is no noise
>  generation mechanism.
>  Gordon. you are referring to regulators, aren't you. They suffer from
>  instability if not decou[led.

>  Specs call-up minimum of 0.22uf on the output and a few uF on the
>  input if more than a few cm away from the supply.
>  The Question was about LEDs

>  Andy
www.g4jnt.com

>  On Sat, 23 Jan 2021 at 20:27, Gordon REASON via groups.io
>  <gordonj.reason=virgin.net@groups.io> wrote:

>  > Yes , Rick , should be decoupled with a 10 or 22 nF and a 4.7 uF .
>  >
>  >> On 23 January 2021 at 19:27 "G8ZHA via groups.io"
>  >> <g8zha-1=blueyonder.co.uk@groups.io> wrote:
>  >>
>  >> I have just built a G4DDK PGA-103 preamp to use for ADSB receive
>  >> on 1090MHz. The preamp will be mounted up on a pole, directly
>  >> underneath a PCB antenna, in a plastic tube. I feed 12V up to the
>  >> preamp and have 5V regulator next to the preamp. I usually include
>  >> a LED on the 5V shining down at the ground, so I can confirm that
>  >> the preamp is powered.
>  >>
>  >> Do LEDs generate any noise?
>  >>
>  >> Rich G8ZHA
>  >
>  >>








--
Robin Szemeti - G1YFG


Re: cling film?

John Fell
 

Ah yes ,
A mini olde style Fylingdales Radome would work .You may find /p operation would bring more attention than you would like and if it was windy ........

Good to see the next generation working through the systems Engineering we had to do on narrowband 10GHz back in the late 1980s ,Such Fun .
73
John
G0API

On Sun, 24 Jan 2021 at 16:34, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Hi Ben,
Polystyrene boxes and cling film are OK for temp /P .
Keep up the good work .
73
John
G0API


Thanks John. 

Should do a little better this year, didn't start in this field until April last year so should get 3 months of extra points, hi.
Thinking on keeping rain off the radiator, a balloon would be good, blown up to cover but not touch the elements but can't get it on, hi. 

Need like a sphere, in two halves, bottom has coax though it first, connected, then bottom and top halves joined together to keep the rain off the radiator, hi. 

All good fun!

Ben 


Re: Are LEDs a noise source

John Fell
 

Yes , I know it was done Yonks ago , but the new software was mentioned in the last issue of the EME Newsletter as one of the "other" uses used to test the software system before general release - using more modest light sources .

I saw a video on TV (Winterwatch) showing a man flushing Starlings out of Italian Trees to prevent Poomagedon .Looked like a solid torch but emitting narrow beamwidth Laser light ?
Now a bit of websearching and modulation interfacing it could be possible to do some handheld OTH comms ....

John


On Sun, 24 Jan 2021 at 16:25, Andy G4JNT <andy.g4jnt@...> wrote:
No, It WAS done yonks ago in Oz, using WSPR just after it first came out

They used 60W of red LEDs, WSPR on a subcarrier and got 200km plus on cloud scatter.

I keep thinking I really ought to have a go at this, get some really big high power RED LEDs and find some suitable optics.    It's difficult getting a non point source into a narrow beam though, needs physically big and thick lenses.



On Sun, 24 Jan 2021 at 16:22, John Fell <john.g0api@...> wrote:
-45dB would probably relate to the developmental WSJT-X software yet to be released .(Done in VK ?)

I have had Transatlantic decodes at -44dB/noise , using JST4W-1800 on 137kHz  - that seems to be the limit but up in the realtime nano metre wavelengths , with massive path scattering a 65 tone or more system would need to be used .
Andy JNT knows more about the Shannon theory ....but all the LEDs in his right side are aching again .I blame the Snow .

It's Bloody clever stuf .

73
John
G0API

On Sun, 24 Jan 2021 at 16:09, Robin Szemeti - G1YFG <robin@...> wrote:
Speaking of which ... there was a rather excellent article in DUBUS a while ago about some chaps resurrecting a 90's LED optical transceiver and adding JT65 or similar to it and getting phenomenal performance ... hundreds of kilometres over non-line-of-sight paths, just relying on atmospheric scattering and recovering signals at -45 dB S/N

On Sun, 24 Jan 2021 at 14:53, Andy G4JNT <andy.g4jnt@...> wrote:
Especially white ones.



On Sun, 24 Jan 2021 at 14:34, John E. Beech <john@...> wrote:
It could be argued that LEDs produce noise at nanometer wavelengths.

de John G8SEQ

>  -------Original Message-------
>  From: Andy G4JNT <andy.g4jnt@...>
>  To: UK Microwaves groups.io <UKMicrowaves@groups.io>
>  Subject: Re: [UKMicrowaves] Are LEDs a noise source
>  Sent: Jan 23 '21 20:36

>  LEDs do not generate noise. Being forward-biassed, there is no noise
>  generation mechanism.
>  Gordon. you are referring to regulators, aren't you. They suffer from
>  instability if not decou[led.

>  Specs call-up minimum of 0.22uf on the output and a few uF on the
>  input if more than a few cm away from the supply.
>  The Question was about LEDs

>  Andy
www.g4jnt.com

>  On Sat, 23 Jan 2021 at 20:27, Gordon REASON via groups.io
>  <gordonj.reason=virgin.net@groups.io> wrote:

>  > Yes , Rick , should be decoupled with a 10 or 22 nF and a 4.7 uF .
>  >
>  >> On 23 January 2021 at 19:27 "G8ZHA via groups.io"
>  >> <g8zha-1=blueyonder.co.uk@groups.io> wrote:
>  >>
>  >> I have just built a G4DDK PGA-103 preamp to use for ADSB receive
>  >> on 1090MHz. The preamp will be mounted up on a pole, directly
>  >> underneath a PCB antenna, in a plastic tube. I feed 12V up to the
>  >> preamp and have 5V regulator next to the preamp. I usually include
>  >> a LED on the 5V shining down at the ground, so I can confirm that
>  >> the preamp is powered.
>  >>
>  >> Do LEDs generate any noise?
>  >>
>  >> Rich G8ZHA
>  >
>  >>








--
Robin Szemeti - G1YFG


Re: cling film?

militaryoperator
 

Hi Ben,
Polystyrene boxes and cling film are OK for temp /P .
Keep up the good work .
73
John
G0API


Thanks John. 

Should do a little better this year, didn't start in this field until April last year so should get 3 months of extra points, hi.
Thinking on keeping rain off the radiator, a balloon would be good, blown up to cover but not touch the elements but can't get it on, hi. 

Need like a sphere, in two halves, bottom has coax though it first, connected, then bottom and top halves joined together to keep the rain off the radiator, hi. 

All good fun!

Ben 


Re: Are LEDs a noise source

Andy G4JNT
 

No, It WAS done yonks ago in Oz, using WSPR just after it first came out

They used 60W of red LEDs, WSPR on a subcarrier and got 200km plus on cloud scatter.

I keep thinking I really ought to have a go at this, get some really big high power RED LEDs and find some suitable optics.    It's difficult getting a non point source into a narrow beam though, needs physically big and thick lenses.



On Sun, 24 Jan 2021 at 16:22, John Fell <john.g0api@...> wrote:
-45dB would probably relate to the developmental WSJT-X software yet to be released .(Done in VK ?)

I have had Transatlantic decodes at -44dB/noise , using JST4W-1800 on 137kHz  - that seems to be the limit but up in the realtime nano metre wavelengths , with massive path scattering a 65 tone or more system would need to be used .
Andy JNT knows more about the Shannon theory ....but all the LEDs in his right side are aching again .I blame the Snow .

It's Bloody clever stuf .

73
John
G0API

On Sun, 24 Jan 2021 at 16:09, Robin Szemeti - G1YFG <robin@...> wrote:
Speaking of which ... there was a rather excellent article in DUBUS a while ago about some chaps resurrecting a 90's LED optical transceiver and adding JT65 or similar to it and getting phenomenal performance ... hundreds of kilometres over non-line-of-sight paths, just relying on atmospheric scattering and recovering signals at -45 dB S/N

On Sun, 24 Jan 2021 at 14:53, Andy G4JNT <andy.g4jnt@...> wrote:
Especially white ones.



On Sun, 24 Jan 2021 at 14:34, John E. Beech <john@...> wrote:
It could be argued that LEDs produce noise at nanometer wavelengths.

de John G8SEQ

>  -------Original Message-------
>  From: Andy G4JNT <andy.g4jnt@...>
>  To: UK Microwaves groups.io <UKMicrowaves@groups.io>
>  Subject: Re: [UKMicrowaves] Are LEDs a noise source
>  Sent: Jan 23 '21 20:36

>  LEDs do not generate noise. Being forward-biassed, there is no noise
>  generation mechanism.
>  Gordon. you are referring to regulators, aren't you. They suffer from
>  instability if not decou[led.

>  Specs call-up minimum of 0.22uf on the output and a few uF on the
>  input if more than a few cm away from the supply.
>  The Question was about LEDs

>  Andy
www.g4jnt.com

>  On Sat, 23 Jan 2021 at 20:27, Gordon REASON via groups.io
>  <gordonj.reason=virgin.net@groups.io> wrote:

>  > Yes , Rick , should be decoupled with a 10 or 22 nF and a 4.7 uF .
>  >
>  >> On 23 January 2021 at 19:27 "G8ZHA via groups.io"
>  >> <g8zha-1=blueyonder.co.uk@groups.io> wrote:
>  >>
>  >> I have just built a G4DDK PGA-103 preamp to use for ADSB receive
>  >> on 1090MHz. The preamp will be mounted up on a pole, directly
>  >> underneath a PCB antenna, in a plastic tube. I feed 12V up to the
>  >> preamp and have 5V regulator next to the preamp. I usually include
>  >> a LED on the 5V shining down at the ground, so I can confirm that
>  >> the preamp is powered.
>  >>
>  >> Do LEDs generate any noise?
>  >>
>  >> Rich G8ZHA
>  >
>  >>








--
Robin Szemeti - G1YFG

2261 - 2280 of 62906